Method for electron beam induced etching of layers contaminated with gallium

Abstract

The invention relates to a method for electron beam induced etching of a layer contaminated with gallium, with the method steps of providing at least one first halogenated compound as an etching gas at the position at which an electron beam impacts on the layer, and providing at least one second halogenated compound as a precursor gas for removing of the gallium from this position.

The invention claimed is: 
     
       1. A method, comprising:
 providing a first gas at a position at which an electron beam impacts a layer including gallium to etch the layer; and 
 providing a second gas to the position to remove the gallium, 
 wherein the method is performed without forming inert residua, the layer is a semiconductor layer or an isolation layer, the first gas is different from the second gas, the first gas is a halogenated gas, and the second gas is a halogenated gas. 
 
     
     
       2. The method of  claim 1 , wherein the first gas comprises xenon difluoride. 
     
     
       3. The method of  claim 2 , wherein the second gas comprises chlorine gas. 
     
     
       4. The method of  claim 1 , wherein the second gas comprises chlorine gas. 
     
     
       5. The method of  claim 1 , comprising continuously providing the second gas. 
     
     
       6. The method of  claim 5 , comprising providing the second gas at a gas flow rate of 0.1 standard cubic centimetres per minute. 
     
     
       7. The method of  claim 1 , comprising temporally varying the provision of the first gas. 
     
     
       8. The method of  claim 7 , comprising providing the first gas with a duty cycle of 1:5 chopped with a clock rate of 30 seconds. 
     
     
       9. The method of  claim 1 , wherein a multi-layered system comprises the layer including the gallium, the method comprises etching a via through the multi-layered system, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching the layers which are not contaminated with gallium. 
     
     
       10. The method of  claim 1 , wherein the method is performed in a vacuum chamber, and a vapour partial pressure in the vacuum chamber is reduced with a cold trap and/or an ultraviolet lamp. 
     
     
       11. The method of  claim 1 , comprising, before providing the first gas, imaging a surface of the layer including the gallium with an electron beam. 
     
     
       12. The method of  claim 1 , comprising, after etching the layer including the gallium, imaging a surface of the layer with an electron beam. 
     
     
       13. The method of  claim 1 , wherein the first gas comprises a gas selected from the group consisting of bromine gas, iodine gas, sulphur hexafluoride and oxygen. 
     
     
       14. A method, comprising:
 variably providing a first gas at a position at which an electron beam impacts a layer including gallium to etch the layer; and 
 continuously providing a second gas to the position to remove the gallium, 
 wherein the first gas is different from the second gas, the layer is a semiconductor layer or an isolation layer, and the method is performed without forming inert residua. 
 
     
     
       15. The method of  claim 14 , wherein the first gas comprises a first halogenated gas. 
     
     
       16. The method of  claim 15 , wherein the second gas comprises a second halogenated gas. 
     
     
       17. The method of  claim 14 , wherein the second gas comprises a second halogenated gas. 
     
     
       18. The method of  claim 14 , wherein the first gas comprises a gas selected from the group consisting of bromine gas, iodine gas, sulphur hexafluoride and oxygen. 
     
     
       19. The method of  claim 14 , wherein a multi-layered system comprises the layer including the gallium, the method comprises etching a via through the multi-layered system, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching the layers which are not contaminated with gallium. 
     
     
       20. The method of  claim 14 , wherein the first gas comprises xenon difluoride, and the second gas comprises chlorine gas. 
     
     
       21. A method, comprising:
 impacting an electron beam on a multi-layered system comprising a layer including gallium; 
 providing a first gas to the multi-layered system to etch a via through the multi-layered system including etching the layer including the gallium; and 
 providing a second gas to the multi-layered system to remove the gallium, 
 wherein the first gas is different from the second gas, the second gas is a halogenated gas, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching layers in the multi-layer system which are not contaminated with gallium. 
 
     
     
       22. A method, comprising:
 impacting an electron beam on a multi-layered system comprising a layer including gallium; 
 variably providing a first gas to the multi-layered system to etch a via through the multi-layered system including etching the layer including the gallium; and 
 continuously providing a second gas to the multi-layered system to remove the gallium, 
 wherein the first gas is different from the second gas, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching layers of the multi-layer system which are not contaminated with gallium. 
 
     
     
       23. A method, comprising:
 providing a first gas at a position at which an electron beam impacts a layer including gallium to etch the layer; and 
 providing a second gas to the position to remove the gallium, 
 wherein the first gas is different from the second gas, the first gas is a halogenated gas, the second gas is a halogenated gas, a multi-layered system comprises the layer including the gallium, the method comprises etching a via through the multi-layered system, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching the layers which are not contaminated with gallium. 
 
     
     
       24. A method, comprising:
 variably providing a first gas at a position at which an electron beam impacts a layer including gallium to etch the layer; and 
 continuously providing a second gas to the position to remove the gallium, 
 wherein the first gas is different from the second gas, a multi-layered system comprises the layer including the gallium, the method comprises etching a via through the multi-layered system, and a gas flow of the second gas is greater when etching the layer including the gallium than when etching the layers which are not contaminated with gallium.